This application is based upon and claims benefit of priority of Japanese Patent Application No. Hei-9-111524 filed on Apr. 28, 1997, the content of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a windshield wiper for cleaning the surface of a windshield of an automotive vehicle.
2. Description of Related Art
There is a tendency that the surface area of a windshield of an automobile becomes larger, and accordingly a longer wiper blade is required. In addition, the curvature of the windshield tends to be larger, and more streamline shape is being employed in an automobile body to improve its aerodynamic characteristics. When a longer wiper blade is used, a higher amount of air flow hits the wiper. Also, most of air flows along the surface of a vehicle body and the windshield when the body is designed with a streamline. As the amount of air or the speed of air hitting the wiper increases, noises caused by the air flow hitting the wiper becomes a problem. The air hitting the wiper and flowing through spaces between levers or between levers and a rubber blade of the wiper causes the noise problem.
Because the wiper usually rests at a position parallel to a lateral direction of a vehicle body (the longitudinal direction of the wiper lies in parallel to the width direction of a vehicle body), more wind flow hits the wiper when the vehicle is driven. To decrease the amount of air hitting the wiper, the wiper is stored in the vehicle body in some automobiles (a concealed wiper) when the wiper is not in use. However, because a special space has to be made in the vehicle body to conceal the wiper, it is not always possible to employ this design. It is especially difficult for small vehicles.
The present invention has been made in view of the above-mentioned problem, and an object of the present invention is to provide a windshield wiper designed to reduce noises caused by air hitting the wiper, and more particularly to provide such an wiper which has a simple structure and can be manufactured at a low cost.
A pair of wipers, each having a wiper arm and blade, rest at the lower end of a windshield of an automobile when they are not in use. They are located in parallel to each other and in parallel to the width direction of the automobile body with a certain overlapped region. They keep that position when the automobile is running, and wind stream directly hits the windshield wipers. When the wind stream flows through the blade, uncomfortable noises are generated.
To reduce such noises, a wind stream guiding surface is formed on a wiper arm which rests in front of or upstream of the other wiper according to the present invention. The wind stream first hits the wiper arm having the wind stream guiding surface, and the wind stream is guided upward or the direction thereof is changed by the guiding surface so that wind does not hit the other wiper located behind the one wiper. The wiper arm includes a wiper head connected to a pivotal shaft and a retainer connected to the wiper head biasing the wiper toward the surface of the windshield. The surface for guiding the wind stream upward is formed on both the retainer and the arm head, or on either one of them. The wind stream guiding surface may be formed by covering the arm head and retainer with a cover having such a surface. The shape of the guiding surface may be variably designed according to wind stream patterns peculiar to any given automobile bodies.
In addition to reduce or avoid the wind stream hitting the other wiper located downstream after it first hits the one wiper located upstream, it may be also needed to reduce or avoid the wind stream hitting the own wiper blade after it first hits the wiper arm to which that wiper blade is connected. To reduce the wind stream hitting its own wiper blade, the guiding surface may be formed also on the wiper arm which is located downstream.
The guiding surface may be either a flat surface or a concave surface ascending from its upstream toward its downstream, as long as an extended line of the guiding surface goes above the wiper located downstream.
By providing the wind stream guiding surface, which has a simple and inexpensive structure, according to the present invention, noises caused by wind stream flowing through the wiper can be effectively reduced.
Other objects and features of the present invention will become more readily apparent from a better understanding of the preferred embodiments described below with reference to the following drawings.